cat and o2 sensors

Gazmo65 · 14th October 2012, 18:25

Ok Iam a little confused I have a 2.0 v6 75 manual 1999 model the cat has started to rattle again and i have toyed with the idea of removing it but was under the impression that the emissions would be out of spec but on investigation the o2 sensor set up is confusing i thought that all systems used a pre cat sensor then a cat and then an after cat sensor but i only have 2 pre cat sensors (its a v6) and then a cat no after cat sensor so is it a guessing game as to the emissions exiting the cat.

mh007 · 14th October 2012, 19:36

Not all cars have Post-Cat sensors.
The Pre-Cat sensors do the job well enough so Post-Cat sensors aren't required on certain systems.
I wouldn't recommend removing the Cat as this may give you other problems aswell as possible future MOT implications.

14th October 2012, 18:25	#1
Gazmo65 Loves to post Volvo S80 Join Date: Feb 2010 Location: Burton Latimer Posts: 268 Thanks: 11 Thanked 39 Times in 20 Posts	cat and o2 sensors Ok Iam a little confused I have a 2.0 v6 75 manual 1999 model the cat has started to rattle again and i have toyed with the idea of removing it but was under the impression that the emissions would be out of spec but on investigation the o2 sensor set up is confusing i thought that all systems used a pre cat sensor then a cat and then an after cat sensor but i only have 2 pre cat sensors (its a v6) and then a cat no after cat sensor so is it a guessing game as to the emissions exiting the cat.

14th October 2012, 19:36	#2
mh007 This is my second home MG ZT260 SE, MG ZT190+, MG ZTT 160, R75 Conn SE 2.0, R75 Conn SE 2.5 X 3, R75 Club SE 1.8, P5B Coupe Join Date: Jul 2009 Location: Keynsham, Bristol Posts: 4,211 Thanks: 65 Thanked 635 Times in 499 Posts	Not all cars have Post-Cat sensors. The Pre-Cat sensors do the job well enough so Post-Cat sensors aren't required on certain systems. I wouldn't recommend removing the Cat as this may give you other problems aswell as possible future MOT implications.